Recovery of Organic Values from TNT Purification Waste Water

118 Propellants and Explosives 2, 118-125 (1977)

a v e r l a g Chemie, GmbH, D-6940 Weinheim, 1977

Recovery of Organic Values from TNT Purification Waste Water E. E. Gilbert

US Army Armament Research and Development Command, Dover, N.J. 07801 (USA)

Riickgewinnung organischer Stoffe aus dern Abwasser der TNT- Reinigung

gestellt, die Extraktion von Mischungen dieser Verbindungen aus dem Abwasser der TNT-Reinigung (“rotes Abwasser”) wurde ausgearbeitet. Die chemischen Reaktionen dieser Sulfonate wurden untersucht, insbesondere im Hinblick auf direkre und indirekte Wege zur Entsulfonierung zu 2,4-DNT. Ebenso wurde die zum 2-Amino- 4-nitrotoluol bzw. 2,4-Diaminotoluol fuhrende Reduktion einer bzw. beider Nitrogruppen mit nachfolgender Entsulfonierung studiert, sowie der Ersatz der Sulfonat-Gruppen durch Chlor-, Hydroxyl-, oder substituierte Amino-Gruppen. Die genannten Reaktionen der reinen Sulfonate wurden groRtenteils auch mit TNT-Isomeren durch- gefiihrt und in einzelnen Fallen auf stabilisiertes rotes Abwasser aus- gedehnt.

Reines 2,4-Dinitrotoluol-3-sulfonat und -5-sulfonat wurden her-

Recup6rations de matieres organiques des eaux ukes de purification de TNT

-5-sulfonate onr ete preparks e t une methode a Ptk dkveloppke pour leur extraction (en mklange) des eaux de purification de la TNT (“eau rouge”). Quelques reactions des sulfonates ont 6tC ktudikes et une attention speciale a ete apportee a la possibilitk de methodes directes ou indirectes pour leur desulfonation en 2,4-DNT. Les autres reactions etudiies incluent la reduction de I’un ou des deux groupements nitro, suivi par disulfonation, donnant le 2-amino-4- nitrotoluene et le Z,+diaminotoluene, respectivement, et le remplace- ment du groupe sulfonate pat le chlore, hydroxyle, et diffkrents groupes amine substituis. La plupart de ces rkactions avec les sulfonates purs o n t ete aussi appliquees aux isomeres du TNT corre- spondants, et dans certains cas, directement A I’eau rouge stabiliske.

Les sels purs de sodium du 2,4-dinitrotoluene-3-sulfonate et du

Summary

Pure sodium 2,4-dinirrotoluene-3-sulfonate and -5-sulfonate were prepared, and a procedure was developed for their extraction (as a mixture) from TNT purificarion waste water (‘red water’). Reactions of the sulfonates were studied, with special emphasis on possible direct and indirect methods for desulfonating them to 2,4-DNT. Other reactions studied included reduction of one or both nitro groups, followed by desulfonation, yielding 2-amino-4-nirrotoluene and 2,4-diamino-toluene, respecrively, and replacement of the sulfonare group by chlorine, hydroxyl, and various substituted amino groups. Most of these reactions with the pure sulfonates were also applied to the corresponding 1”T isomers, and in some cases directly to stabilized red water.

1. Introduction

During the production of TNT, about 4.5% of the crude product comprises objectionable unsymmetrical TNT isomers, principally 2,4,5- and 2,3,4-trinitrotoluene, which must be removed to achieve suitable military purity. This is commonly done by treating the crude TNT with aqueous sodium sulfite (‘sellite’), which reacts with the isomers forming sodium 2,4-dinitro-toluene-5-sulfonate and -3-sulfonate, respectively, to be referred to herein as DNT-5-S03 Na and DNT-3-S03 Na. The reaction is as follows:

The water-soluble sulfonates are removed in the spent sellite solution (‘red water’) in the proportion of about 1.0 part of the 5-isomer to about 0.6 part of the 3-isomer.

I t has long been recognized that red water presents a disposal problem, and that recovery of the sulfonates in usable form would help to alleviate it, as well as to possibly reflect monetary credit for the process as a whole. The present study was accordingly undertaken to obtain a better knowledge of the chemistry of the sulfonates toward chat end. Such studies - to be cited in detail later - have of course been made in the past, but they were made many years ago and were quite limited in scope.

2. Preparation of the Pure DNT Sulfonate Isomers

All of our studies were made initially with the pure sulfonates; promising reactions were then tried directly with red water. DNT-5-S03Na was made by reaction ( 1 ) from 2,4,5-TNT and aqueous sodium sulfite by modifying the method of Brady et al.(’), and DNT-3-S03Na was made similarly by modifying the procedure of Gornall and Ro- binson(’). Details of both are given in the experimental section. The required 2,4,5- and 2,3,4-TNT isomers were prepared by the improved method described by Dennis er d3), involving rhe nitration of 3,4-DNT and 2,3-DNT, respectively. During the course of this study, those DNT isomers became commercially unavailable. A simplified procedure for their preparation was therefore developed, starting from the corresponding available n i t ro t~ lu id ines(~) . DNT-5-S03Na has recently also been prepared by dinitrating 3-chlorotolu- ene, converting rhe dinitro compound to bis(2,4-dinitro-5- methylphen I)disulfide, and oxidizing it to the desired sulfonic a ~ i d ( ~ Y We did not employ this method, since attempted preparation of DNT-3-S03Na by this procedure was unsuccessful at the last step.

During our preparation of DNT-5-S03Na, acidification of the residual mother liquor gave a solid by-product exploding

Propellants and Explosives 2, 118-125 (1977) Recovery o f Organic Values from T N T Purification Waste Water 119

a t 145 OC; this compound is discussed in more derail in the section on hydrolytic desulfonation, and in the experimental section.

3. Isolation of the Sulfonate Mixture from Red Water

Reactions found promising with the pure sulfonates were in some cases tried with 'stabilized' red water, the preparation and analysis of which are described in detail elsewhere(6). Red water as obtained from the TNT plant is alkaline (pH 8.4), and slowly decomposes upon standing. To effect stabi- lization, i t was acidified to pH 3.7 with 25% sulfuric acid, allowed to stand one week, and filtered. The filtrate was then extracted successively with benzene and ether. The total of the solids obtained by filtration and by evaporation of the solvents amounted to 0.47% of the weight of the red water, and the major constituent was 2,4,6-TNT.

results(6) in %: The stabilized red water was analyzed, with the following

Inorganics 5 -8 DNT sulfonares 4.5 'Red Tar' 8.5 Total 18-21

The red tar is thought(6) to comprise organic sulfonates derived from 2,4,6-TNT as the result of overly drastic conditions of selliting. I t was anticipated that it might interfere with our attempts to isolate reasonably pure products from the sulfonates by direct reaction of the stabilized red water, especially with amino compounds. I t was found, however, that in most cases the desired products could be obtained in reasonabie yiekd and purity without interference f rom the red tar.

red water was studied briefly in the present program. I t was evaporated to dryness and extracted with boiling 90% isopropanol, which was found to dissolve the sulfonates, but not the red tar. Distillation of t h e solvent gave a 6.9% yield of solid. Thin-layer chromatographic analysis(6) indicated a sulfonate content of about 90%. Further evidence was obtained by nitric acid oxidation of the extracted solids. A blank experiment was first run in which pure DNT-5-S03Na was refluxed for 6 hours with 60% nitric acid at 118 "C. No fuming or other evidence of oxidation was noted, and the sulfonate was recovered unchanged in quantitative yield. A sample of material extracted from red water solids with 90% isopropanol was then treated similarly. Some fuming was noted. Workup gave an 80% yield of a friable yellow solid found by NMR analysis to comprise 61% DNT-5-S03Na, 39% DNT-3-S03Na, and some inorganic material.

Isolation of the solid sulfonate mixture from the stabilized

4. Desulfonation to 2,4-DNT

Many types of aromatic sulfonic acids can be desulfonated, replacing the sulfonic group by a proton. Applicarion of this reaction to the two DNT-sulfonate isomers would give 2,4-DNT, as follows:

This approach is obviously of prime interest, since the 2,4-DhT could be recycled to the nitration step, thereby increasing the yield of the desired 2,4,6-TNT, while disposing of a troublesome by-product. Several direct and indirect desul- fonarion procedures have been considered, as discussed below.

4.1. Direct desulfonation studies

4.1.1. Hydrolytic desulfonation

Desulfonation by heating in an aqueous acid medium has been widely used for research and industrial purposes(7). Unfortunately, nitroaromatic sulfonic acids have been found to unique1 resist hydrolytic desulfonation. Vesely and StojanovaY8) reported that 2-nitro-, 3-nitro- and 4-nitrobenzenesulfonic acids d o not undergo desulfonation in phosphoric acid. They give n o experimental details, but did obtain satisfactory desulfonation with 15 other sulfonic acids, including benzenesulfonic a t 227 OC. Brady et al.('), refer- ring to DNT-3-S03H and DNT-5-S03H, state that "all attempts to remove the sulfo group by hydrolysis, with production of the dinitrotoluenes, have been unsuccessful", bu t give no details. In a recent study, no reaction was noted upon heating DNT-5-S03H with aqueous sulfuric o r phosphoric acids in the range 1 3 0 OC-150 "d9). 4-Chloro-3,5-dinitrobenzenesulfonic acid resisted desulfonation at 1 7 0 "C with 60% sulfuric acid under pressure("). On the other hand, desulfonation was noted with three tri- and tetrabromonitrobenzene- sulfonic acids in the range 180 OC-230 "C('O), and with several nitrobenzenesulfonic acids also containing amino or hydroxyl groups(").

temperatures and pressures than used heretofore, and also with trifluoromethanesulfonic acid, which we have found to give improved results in some cases("). No desulfonation was noted with 4-nitro-, 2,4-dinitro-, o r 2,4,6-trinirrobenzenesul- fonic acids in phosphoric o r trifluoromethanesulfonic acids at atmospheric pressure at temperatures as high as 300 OC, even though the expected results were obtained in check ex- periments with other sulfonic acids. A series of tests was then run with DNT-5-S03Na using 30%-43% phosphoric acid under pressure a t 200 OC for 1-5 hours. No reaction occurred at the shorter times, and with longer periods of heating only decomposition was noted. I t was therefore concluded that rhermal hydrolytic desulfonation is not a promising approach to recovery of the DNT sulfonates.

to effect hydrolytic desulfonation by heatin red water in a closed vessel at 1 5 0 "C with phosphoric acid?"). In one experiment, a violent explosion occurred, for which no expla- nation is given. An earlier paper by Batik('4), however, reports isolation of a water-insoluble compound exploding at about 140 O C upon the acidification of red water. This compound was assigned the following structure:

We decided to at tempt this type of desulfonation a t higher

Mention should be made of a reported unsuccessful effort

I t was thought to result from the reduction and diamti- zation of the 4-nitro group in DNT-5-S03Na. A water-in-

120 E. E. Gilbert Propellants and Explosives 2, 118-125 (1977)

soluble compound exploding at 145 OC was indeed isolated during the present study upon acidification of the filtrate from a preparation of DNT-S-SO3Na from 2,4,5-TNT and sodium sulfite, as detailed in the experimental section. Care should therefore be taken to filter acidified red water before it is heated.

4.1.2. Reductive desulfonation

This approach involves removal of the sulfonic group by a reducing agent, but without reduction of the nitro groups. Reductive desulfonation was attempted with DNT-5-S03Na by Dennis et ai.(5), who obtained a 5% yield of 2,4-DNT using sodium borohydride; this reaction was not studied further.

Reductive desulfonation of 2,4,6-trinitrobenzenesulfonic acid to trinitrobenzol (TNB) using N-benzyldihydronicotin- amide at room temperature, has been recently reported(15). Conversion of 2,6-dinitrobenzenesulfonic acid to 1,3-dinitrobenzene by this procedure has also been noted(' 6 ) ,

although the reaction was greatly hampered by the lack of a third negative substituent on the ring. We have confirmed this preparation of TNB from the sulfonic acid, but have obtained negative results with 2,4-dinitrobenzenesulfonic acid, and with DNT-5-S03Na. Similar results were noted with N-ethyldihydronicotinamide.

In spite of these negative results, it is felt that reductive desulfonation should be studied further using other reducing agents and under varied conditions.

4.2. Indirect desuljonation studies

Indirect desulfonation involves conversion of the DNT sulfonate isomer mixture to 2,4-DNT via an intermediate compound. Three methods for effecting this were considered, as follows.

4.2.1. Via 3-amino- and 5-amino-2,4-dinitrotoluene

This concept involves the following reactions:

As noted subsequently, a mixture of the two amino DNT isomers can be obtained easily by heating red water with ammonia under pressure (reaction (3 A)). The mixture was isolated in good purity by simple filtration, but in only poor to fair yields. Reaction (3 B)(I7) gave a 72% yield of 2,4-DNT from 5-amino-2,4-DNT. However, the 3-amino compound under the same conditions gave only 22%.

For this route to be of practical interest, it would be necessary to improve the yields of both steps, and to use a cheaper diazotizing agent than butyl nitrite (BuONO).

4.2.2. Via 5-hydrazino-2,4-dinitroroluene

As detailed in the next section, the following new reaction (4A) was noted:

(4)

ko2

Reaction ( 4 B ) is known in the case of 3-hydrazino-2,4-DNT, but no yield is given('*). Using silver oxide or copper sulfate as oxidants("), we obtained 12-17% yields in reaction (4B).

This approach is of no practical interest because DNT-3- SOjNa does not undergo reaction (4A), hydrazine is expen- sive, and the yield in reaction ( 4 B ) is low.

4.2.3. Via 3-chloro- and 5-chloro-2,4-dinitrotoluene

The following reactions are involved in this approach:

+ HCI ( 5 )

T T H' NO2 NO2 NO2 DMF

Reaction ( 5 A) is known in the case of 2,4,6-trinitroben~ene-(~') and 2,4-dinitrobenzenesulfonic acids(*'), and we have found that DNT-5-SO3Na can be converted to 5-chloro-2,4-DNT by this procedure. However, under the same conditions, DNT-3-SO3Na gave the corresponding sulfonyl chloride, rather than the desired 3-chloro-2,4-DNT. Some sulfonyl chlorides can be thermally desulfonated by the following reaction:

R S O ~ C I H ~ ~ ~ R C I + soz

However, we were unable to prepare 3-chloro-2,4-DNT by this method. 3-Chloro- and 5-chloro-2,4-DNT were both prepared from the corresponding TNT isomer by reaction (7), which is known in the case of the latter compound(2').

RNOz + POCl3 RC1+ NO, (7)

Replacement of chlorine by hydrogen using reaction (5 B) is known for other compounds(22), and we have applied it to the conversion of 3-chloro- and 5-chloro-2,4-DNT to 2,4-DNT.

does not undergo reaction (5 A), and because of the cost of the other reagents needed.

This approach is of limited interest because DNT-3-S03Na

5 . Desulfonation with Nitro Group Reduction

5.1. Conversion to 2,4-diaminotoluene

This concept involves the following reactions (8) (see page 121). I t appeared of potential practical interest since there is a large commercial market for diaminotoiuenes to make polyurethane resins, and since reactions (8 A) is a type al- ready widely used commercially.

Propellants and Explosives 2, 118-125 (1977) Recovery of Organic Values from TNT Purification Waste Water 121

(A) Na03S + Na0,S

Reduction of DNT-5-S03Na with iron and hydrochloric acid gave a 60-75% yield of the corresponding diamino compound, while reduction with iron and sulfuric acid resulted in reduction of the 2-nitro group only, a result similar to that obtained with sulfur dioxide, as reported later. Direct treatment of red water with iron and hydrochloric acid gave a 40% yield of the diamino compound. This type of reduction is now ordinarily done commercially using hydrogen with a catalysr. Use of this approach with sodium 2,4-dinitrobenzenesulfonate gave the theoretical uptake of hydrogen for the reduction of both nitro groups; this approach was not tested with the DNT sulfonate isomers.

Although hydrolytic desulfonation, as noted previously, could nor be effected wirh rhe DNT sulfonate isomers, such was readily achieved (reaction (8 B)) wirh the corresponding diamino compound, 2,4-diamino-toluene-5-sulfonic acid. A 90% yield was obtained by refluxing with 65% sulfuric acid (cf. experimental section). The reaction was not studied with the corresponding 2,4-diaminotoluene-3-sulfonic acid.

The above results are considered fairly promising, and the process may warrent further study.

5.2. Conversion to 2-amino-4-nitrotoluene

I t was thought thar a simplified, ‘one-por’ approach to reaction ( 8 ) might comprise simply heating the DNT sulfonates with aqueous sulfur dioxide under pressure, This would eliminate a separate reduction step, since the nitro groups should be reduced to amino by the sulfur dioxide, which would be converted thereby to suifuric acid. The acid would rhen caralyze desulfonation t o 2,4-diaminotoluene.

To test this concept, sodium 2,4-dinitrobenzenesulfonate was heated three hours ar 215 OC under pressure with 6% aqueous sulfur dioxide. 3-Nitroaniline was obtained in 29% yield, evidently resulting from partial reduction, followed by desulfonation. This experiment was repeated with DNT-5-S03Na for 3 hours at 180 “C. I t was found thar 31% was converted to 2-amino-4-nitrotoluene, 35% of the starting compound was recovered, and 34% was unaccounted for. A similar test. with DNT-3-S03Na gave a 29% conversion to 2-amino-4-nitrotoluene. The reactions are:

NO2 so* .--) Nao3s@Hz1--. . @H2 (9)

NO2 NO2

NaOJS 4 H20

NO2

Tests were then run wirh stabilized red water, which was saturated with SO2 gas ar 10 “C, followed by heating 3 hours at 180 “C under pressure. The yield of 2-amino-4-nitrotoluene was 43% based on the reacted sulfonates. A similar yieId was obtained at 165 OC for 3 hours.

This approach may be worth further study toward ob- taining higher yields and the reduction of both nitro groups.

6. Reaction of the DNT Sulfonates with Amino Compounds

Little work has been reported on the reaction of amino compounds with the DNT sulfonate isomers. M ~ r a o u r ( ~ ~ ) states that DNT-5-SO3Na reacts with ammonia forming the ,

corresponding dinitrotoluidine, but gives no details. Brady et al.(’) state that ammonia does not react ‘readily’ with it, but that methylamine forms the corresponding substituted dinitrotoluidine; no details are given. A British report(24) states that both DNT sulfonate isomers react with methylamine, and proposes nitration of the resulting N-methyl- dinitrotoluidine mixture to ‘methyl tetryl’ as a method for red water utilization. Dennis and Rosenblatt(’) show that methylamine reacts easily with DNT-5-S03Na to give a good yield of product. The reaction is:

Nao3s@ - RNH? RNH 4 N 0 2 + NaHS03 (10)

This reaction was extended in the present study to include the use of ammonia, hydrazine, and various aliphatic and aromatic amines. Initial work was done with the two pure DNT sulfonate isomers preliminary to the direct use of red water. The same derivatives were also made in all cases by reaction of the same amino compounds with the analogous TNT isomers.

NO2 NO2

6.1. Amino compounds with pure DNT sulfonate isomers

The data are summarized in Table 1. I t is noted that DNT-5-S03Na usually forms the corresponding 5-amino derivatives in fair to good yields except for morpholine, rhe only secondary amine tried other than dimethylamine. Ani- line required drastic reaction conditions.

On the other hand, DNT-3-S03Na showed little or no reaction wirh hydrazine or dimethylamine, and often gave lower yields than DNT-5-S03Na with other amines. This may be explained by greater sreric hindrance in the 3-isomer.

I t thus appears rhat facile reaction with both sulfonate isomers is limited to ammonia and the primary aliphatic amines, with ammonia reacting less easily than the amines, probably because of its iower basicity.

I t is of interest that the sulfonates react much less easily than the corresponding TNT isomers to form the same products. This is especially true with amines of low basicity, i.e. aniline. Dennis and Rosenblatt(’) noted that the rate constant for the reaction of methylamine with DNT-5-S03Na is 250 times less than thar with 2,4,5-TNT. DNT-3-S03Na, as noted above, did not reacr with dimethylamine or hydrazine; the desired derivatives were, however, easily prepared from 2,3,4-TNT.

The reaction with ammonia was first tested with the benzene analogue sodium 2,+dinitrobenzenesulfonate. The rea- genrs were heated in aqueous solution in a pressure bottle with stirring. The expected 2,4-dinitroaniline was obtained in 70% maximum yield; the yield was raised to nearly quantitative by adding barium chloride to fix the liberated sulfite


Table 1. Reaction of Ammonia, Hydrazine and Amines with Pure 2,4-DNT-S03Na Isomers

Compound 3-SO 3Na Percent Melting Point 5-S03Na Percent Melting Poinr Reacted Conditions (a) Yield (b) 'This Lit. Conditions (a) Yield (c) This Lit.

(Hours] ["C] [%I study (d) [Hours] ["C] [%I study (d)

Ammonia Hydrazine Methylamine Dimethylamine n-bury lamine Isopropylamine Isobutylamine n-Dodecylamine Cyclohexylamine Morpholine Aniline

1-2 4-24 1.5 2.0 0.5 0.5 0.5 0.5 0.5 - -

95 25-95 25 90 9 0 9 0 90 90 90 -

-

30-36 0-5

80 < 5 84 35 67 90+ 86 -

-

9 4 167

76 Oil Oil

95 53

Oil Oil

7 3 115

1 95 (e) 16 25

1.5 25 1.5 25 0.5 90 0.5 9 0 0.5 90 0.5 95 0.5 95 1 95 7 150 (e)

40-74 77 8 5 8 2 90+ 75 92 8 3 86 (h) 1 4 38-58

194 195(23) 195 194(26) 171 173(27) 110 1137(~')

95 96(28) 69 (f) 88 112 (g)

~ ~~

(a) All runs made with excess amine in dilute aqueous solution. (b) Of 3-alkylamino-2,4-DNT. (c) Of 5-alkylamine-2.4-DNT. (d) Of products prepared from the corresponding TNT isomer; the products made from the sulfonates were proven identical by NMR

(e) Run under pressure. (f) New compound. (9) Literature m.p. concluded to be Incorrect. (h) Yield 43% in 0.1 hours.

and/or IR spectra.

ion. The ammonia reaction was then tried with DNT-5-S03Na by heating 1 hour at 95 "C with excess 30% ammonium hydroxide in a pressure bottle. The best yields, using adding barium chloride, were 75%-85%. DNT-3-S03Na, as expected gave a 36% yield under conditions which gave 59% with the 5-isomer and 72% with the benzene analogue.

is apparently novel, and is quite specific. DNT-5-S03Na and sodium 2,4-dinitrobenzenesulfonate yield the corresponding hydrazino derivatives, but the former did not react with phenylhydrazine, 1,l dimethylhydrazine, hydroxylamine, or guanidine. Hydrazine does not react with DNT-3-S03Na in appreciable yield, and not at all with 4-nitrobenzenesulfonic acid.

The reaction of hydrazine with aromatic sulfonate salts

both temperatures. Use of the higher temperature is un- desirable with hydrazine, but with the other compounds leads to a good yield as opposed to a low one at 25 'C. Several of the amines (methyl, isopropyl, n-butyl, isobutyl and cyclohexyl) gave products with isomer ratios close to those of the sulfonates in the red water, showing that both isomers react completely. As stated above, the amino compounds were always applied in large excess.In the case of ammonia and hydrazine, the yields declined if the amount of excess reagent was reduced; this was not studied with the other compounds. This point should be addressed in any further work, as should also the ease of recovery of the excess reagent. Use of more concentrated solutions obtained by partial evaporation of the red water should also be considered.

6.2. Amino compounds with stabilized red water 7. Hydrolysis of the DNT Sulfonates to Dinitrocresols

With the above studies using pure sulfonate isomers as background, the same amino compounds were reacted directly with stabilized red waxer. The runs were made at 25 OC and 95 OC, using a large excess of amino compound in all cases. The products from ammonia, hydrazine, methylamine, dimethylamine, and isopropylamine were all solids easily recoverable by simple filtration of the reaction mixture. On the other hand, the products from n-butylamine, isobutylamine, n-dodecylamine and cyclohexylamine were semi- solid, being mixtures of the solid 5-isomer and the liquid (or low-melting) 3-isomer. These were isolated by extraction with chloroform; the mixture was recovered as a semi-solid by evaporation of the solvent.

The results are summarized in Table 2. In general, i t is noted that they parallel those obtained with the pure sulfonates. Morpholine and aniline gave very poor yields, while hydrazine and dimethylamine react only with DNT-5-S03Na. Ammonia is unique in forming no product at 25 OC, while

This approach, involving the following reaction, was considered potentially interesting for recovery of organic values:

ho, h0,

The literature(") reports that this type of reaction is known for sodium 2,4-dinitrobenzenesulfonate, but it apparently has not been extended to the DNT sulfonates. Hydrolysis of the former compound to 2,4-dinitrophenol was accordingly checked with several bases, by refluxing 1 hour in aqueous medium, with yields as follows: MgO (0%), NaHC03 (22%), Na2C03 (28%), NaOH (61%), Ca(OH)2 (83%), Ba(OH), (84%). With these results as background, the hydrolysis of DNT-5-S03 Na was attempted similarly, using NaOH and Ba(OH)2. Surprisingly, no cresol was obtained. Both cresols methylamine and dimethylamine give the same yields at - .


Table 2. Reaction of Ammonia, Hydrazine and Amines with Red Water

Compound Reacted Red Water Analysis (c) Percent

g Product per 100 ml

25 "C (a) 95 "C (b) 5-isomer 3-isomer Yield (d)

Ammonia Hydrazine Methy lamine Dimethy lamine n-Butylamine Isopropylamine lsobutylamine n-Dodecylamine Cyclohexylamine Morpholine Aniline

O(24) 2.2(7) 3.6(1.5) 1.8( 1.5) 1.8(5.5) 0.8(7) 1.4(16)

1.8(24) -

- -

1.6 (e, f ) 1.5 (e) 3.8 (e) 1.8 (e) 4.5 3.4 4.4 3.4 5.6 Low < 1.5 ( i )

72- 100

57 100

. 55 57 52

57 (h)

- -

-78 22-28 0

4 3 0

45 43 48 (h) 43 -

-

2 3 -46 90+ (g) 90+ 75 (g) 90+ 81 90+ 90+ 90+ - < 38

(a) Hours at 25 OC given parenthetically. (b) All runs at 0.5 hours, except as indicated. (c) Of product prepared at 95 "C, by NMR, % given of designated alkylamino isomer. (d) Crude yield of both isomers obtained at 95 O C , except as indicated, based on analysd6)

(e) Run under pressure. (f) Three hours reaction time. (g) Yield expressed on the basis of 5-SO3Na content. (h) Analysis showed about equal amounts of the two isomers plus an impurity derived from

dodecy Iamine. ( i ) Run at 160 "C under pressure for three hours.

showing 2.5 g sulfonates (mol. wt. 284, 58% 5-isomer, 42% 3-isomer) per 5 0 ml (56 g).

were easily prepared in good yield from the corresponding TNT isomers, however, by an improved procedure detailed in the experimental section.

8. Experimental

Melting points were taken in a Thomas-Hoover melting point apparatus and are uncorrected. Infrared spectra were determined in KBr pellets with a Perkin-Elmer Model 457 A spectrophotometer. NMR spectra were obtained with a Va- rian T-60 spectrometer using tetramethylsilane as internal reference, and solvents as indicated (s = singlet, d = doublet, m = multipler).

water were heated with magnetic stirring to 60 OC. A solution of anhydrous sodium sulfite (28 g-0.22 mol, 10% excess) in 125 ml water was added dropwise over 10 minutes, after which the solution was stirred for 30 minutes at 60 OC-65 'C. The solution was decanted from 0.5g unreacted TNT, and cooled overnight to crystallize rhe first crop of product, which was filtered. The filtrate was cooled in an ice bath and a second crop was obtained. The filtrate was taken to quarter valume, and cooled to yield a third crop. The crops were dried to constant weight, the weights being 29.0g, 9.0g and 4.1 g, respectively, toral 42.1 g (72%). Elemental analysis showed the product to be anhydrous. I t is sufficiently pure for most purposes, but can be recrystallized from 90% isopropanol if desired. I t is completely soluble in water (showing the absence of unreacted TNT) and in DMF (indicating the absence of inorganic salts). IR spectrum (KBr): 3580,

(S03Na), 1050 (S03Na), 910, 830 (lone ring H), 710, 630, 590, 560, 420 [cm-' 1. NMR (D20), 6: 2.706, 3H, CH3), 8.12 (s, l H , C6H), 8.48 (s, lH, C3H) [ppm]. Acidification of the dark red filtrate from the third crop with 10% HCl gave a solid (1.9 g), which decomposed explosively at 145 OC. (The structure of this compound is given in the section on

2,4-DNT-5-S03 Na. 2,4,5-TNT (45.4 g-0.2 mol) and 100 ml

3460, 3100, 1630, 1520 (NO*), 1400, 1360 (NOz), 1225

hydrolytic desulfonation). Acidification of the filtrate from a run made at room temperature gave 5-hydroxy-2,4-DNT, rather than the explosive compound. A run similar to the above, but using equivalent sodium sulfite, gave 1.1 g unreacted TNT and a 92% yield of sulfonate. Reaction at room temperature for 24 hours by the method of Brady et al.(') gave a product containing both unreacted TNT and inorganic salts.

2,4-DNT-3-S03Na. 2,3,4,-TNT (11.0 g-0.049 mol) and 20 ml water were heated with magnetic stirring to 65 OC, and a solution of anhydrous sodium sulfite (8.0 g-0.064 mol, 30% excess) in 40 ml water was added dropwise over 10 minutes, after which the solution was stirred for 30 minutes at 75 OC-80 OC. The clear solution (there was no unreacted TNT) was held at 0 "C for an hour to induce crys- tallization; the solid was filtered and washed with a sr .all quantity of ice water. The filtrate was evaporated to 30 ml and again crystallized and filtered. The two crops were air dried to constant weight: 7.8g + 3.8g = 11.6 g (75% of theory). Elemental analysis showed the product to be a 2.5 hydrate, in agreement with the literature@). IR spectrum (KBr): 3500, 3100, 1620, 1530 (NO2 ), 1360 (NO2 ), 1250 (SO3 Na), 1180, 11 30, 1050 (SO3 Na), 930, 850 (two adjacent aromatic protons), 760, 720, 615 [cm-'1. NMR (D20),

The above procedure is essentially that of Gornall and Robin- sont2). Acidification of the filtrate from this preparation, unlike that cited above for the 5-sulfonate, did not give an explosive precipitate; much NO, was evolved.

(5.Og--18 mmol), iron filings (40 mesh, 5.0 g-90 mmol), concentrated hydrochloric acid (1.0 ml) and water (75 ml) were mixed and refluxed 0.5 hours with vigorous agitation. The hot solution was filtered rapidly, and acidified TO pH 1.0 by adding 1.0 ml concentrated hydrochloric acid. The precipitated product was filtered and dried. The yield was 2.3g (58%). Titration with 1.0 N sodium hydroxide gave agreement with the assigned structure. IR (KBr): 3460, 3 360, 2950,

6: 2.70 (s, 3H, CH3), 8.12 (s, lH, CsH), 8.48 (s, lH, CsH).

2,4-Diaminotoluene-5-S03H. 2,4-DNT-5-S03Na


2600,1640,1590,1510,1500,1465,1420,1300,1180,1060, 1040, 995, 910, 840, 670, 560, 400 [cm-' 1. Analysis: cal- culated for C7HIoN203S: 41.5% C, 5.0% H, 13.9 N, 15.8 S; found: 41.5% C, 5.0% H, 14.0% N, 15.7 % S. 2,4-Diamino- toluene-3-S03 Na was similarly prepared by Gornall and Ro- binson(').

2,4-Diaminotoluene. 2 ,4-Diaminotoluene-5-S03 H (20 g-0.1 mol) was suspended in 200 g 65% sulfuric acid and the mixture was refluxed with stirring for 7 hours (148 OC to 155 "C) as the sulfonic acid gradually dissolved. The solution was cooled, crystallized, and filtered to recover 2,4- diaminotoluene sulfate. The filtrate was restored to 200 g with fresh 65% acid and the cycle was repeated four times. The combined product was dissolved in water and neutralized to liberate 2,4-diaminotoluene, which was identified by melting point and 1R spectrum. The yield, including that present in the final filtrate, was 90%. The final filtrate can presumable be recycled several more times before it must be discarded

Reactions with Ammonia. 2,4-DNT-5-S03 Na (2.8g-10 mmol) and 30% ammonium hydroxide (25 ml) were heated 1 hour with magnetic stirring in a pressure bottle at 90 OC. The mixture was cooled and the solid was filtered and dried. The yield of crude 5-amino-2,4-DNT was 1 .O g (53%), m.p. 190-4 OC, Ref. 23: 194-5 "C. The yield was increased to 75% by the addition of 10 mmol barium chloride. I t was also prepared in 85% yield by stirring a toluene solution of 2,4,5-TNT with 30% ammonia at room temperature for 24 hours.

2,4-DNT-3-S03 Na similarly gave a 30% yield of 3-amino- 2,4-dinitrotoluene with 30% ammonium hydroxide. I t was also made in 84% yield by stirring a toluene solution of 2,3,4-TNT with 30 ammonium hydroxide at room temperature for 7 hours. M.p. 91-4 OC, Ref. 31: 9 4 "C.

xide (40 mi) were heated 3 hours at 95 OC in a pressure bottle with magnetic stirring. The mixture was cooled and filtered, yielding 3.1 g yellow solid. NMR analysis showed that it con- tained 72% 5-amino- and 28% 3-amino-2,4-DNT, a yield of 46%.

Stabilized red water (200 ml) and 30% ammonium hydro-

Reactions with n-Butylamine. 2,4-DNT-5-S03 Na (1.4g-5 mmol), n-butylamine (2.5 g-34 mmol), and water (50 ml) were mixed and refluxed with magnetic stirring for 0.5 hours. The mixture was cooled and filtered, yielding 1.2 g (100%) of 5-n-butylamino-2,4-DNT. The IR spectrum was identical with that of a sample made from 2,4,5-TNT by a published procedure('8), m.p. 95 OC, Ref. 28: 96 OC.

2,4-DNT-3-S03 Na reacted similarly with n-butylamine to yield an oily product, which was extracted with chloroform, water washed and dried. Removal of the solvent gave 0.5 g (84%) of an oil, identified as 3-n-butylamino-2,4-DNT by NMR spectrum. NMR (deuteriochloroform) 6 [ppm]: 6 8.23 (d upon broad NH, 2 H, C5 H + NII) J 9 Hz; 6 6.62 (d, 1 H,

CH3); 6 1.83-0.83 (m, 7 H, n-propyl). Stabilized red water (200 ml) and n-butylamine (10 g)

were mixed and refluxed for 0.5 hours. The cold reaction mixture was decanted to remove residual red water, and the semi-solid product was washed twice by decantation. Chloro- form (50 ml) was added to dissolve the product, and the solution was washed successively with 10% hydrochloric acid and with water. Evaporation gave 8.8 g (100%) of a

C6H) J 9 Hz; 6 3.17 (m, 2H, N-CHZ); 6 2.37 (s, 3H, aryl

deep red oil, which solidified on standing to a semi-solid. NMR analysis showed i t to comprise 55% 5-n-butylamino- and 45 % 3-n-butylamino-2,4-DNT.

5-Chloro-2,4-dinitrotoluene. 2,4-DNT-5-S03 Na (2.8 g-10 mmol), phosphorus oxychloride (46 g-300 mmol), and dimethylformamide (1.5 ml) were mixed and heated with magnetic stirring at gentle reflux for 1 hour. The mixture was cooled and mixed carefully with ice water to destroy the residual phosphorus oxychloride and to precipitate the solid product, which was filtered and dried. The yield of crude product was 1.9 g (85%); m. p. 87-9 OC (ex cyclohexane) (Ref. 32: 90--90.5 "C). NMR (acetone-d6 ), 6[ppm]: 6 8.73 (s, lH, C3H);6 7.95 (s, lH, C6H);6 2.73 (s, 3H, CH3). Thecom- pound was also prepared from 2,4,5-TNT and hosphorus

verted to 2,4-DNT in 33% yield by heating 0.5 hours at 155 OC with copper powder and acetic acid, using dimethylformamide as solvent(").

oxychloride by the method of Sbarskii et al. (2 P, . I t was con-

3-Chloro-2,4-dinitrotoluene. I t was prepared similarly from 2,3,4-TNT in 95% crude yield, m.p. 93 OC (ex cyclohexane), Ref. 18, 92 OC. NMR (acetone-d6), 6 [ppm]: 6 8.25 (d, lH ,

CH3). I t was converted to 2,4-DNT in 42% yield by heating with copper powder and acetic acid as mentioned above.

C5 H) J = 9 Hz; 6 7.78 (d, lH , C6H) J = 9 Hz; 6 2.50 (s, 3H,

5-Hydroxy-2,4-dinitrotoluene. 2,4,5-TNT( 1.1 g-5 mmol), finely powdered sodium bicarbonate (1.0 g-12 mmol), and dimethylformamide (10 ml) were mixed and stirred at room temperature for 3 hours. The mixture was poured into water giving a clear yellow solution. Acidification with hydrochloric acid precipitated the product as a cream-colored solid. The yield was 0.8 g (SO%), m.p. 68 "C (ex water), Ref. 1: 73 OC. 3-Hydroxy-2,4-dinitrotoluene was prepared similarly in 80% yield. This procedure is a considerable improvement over that reported('), which is laborious and gives poor yields for borh compounds.

9. References

(1) 0. L. Hrady, S . W. Hewetson, and L. Klein. J . Chem. Soc. 125, 2 4 0 0 (1924) .

( 2 ) E'. H. Gornall and K. Robinson, ihzd. 127, 1981 (1926) . ( 3 ) W. H. Dennis, Jr . , D. H. Rosenblatt, W. G. Blucher, andC. L.

Coon, J . Chem. Eng. Data 20 (2) , 2 0 2 (1975) . (4) E. E. Gilbert and J . K. Leccacorvi, Propellants and Explosives

I , 8 9 (1976) . ( 5 ) W. H . Dennis, Jr . , and D. H . Kosenblatt, Reactions of TNT

Isomers wi th Nucleophiles, Progress Reports dated 16 March and 27 April, 1972, Contract PKON GG 02598601GGP4.

( 6 ) 'I. N. Hall and G. W. Lawrence, A Study of the Organic Com- ponents of Red Water, Naval Surface Weapons Center, White Oak Laboratory, Technical Report 76-123, October 26, 1976.

( 7 ) E. E. Gilbert, Sulfonatzon and Related Reactions, Chapter 8 , Wiley-Interscience, New York 1965.

( 8 ) V. Vesely and T Stojanova. Collr,ct. Czech. Chem. Cornmun. 9, 465 (1937) .

(9) J . I-. Spencer, Study ofMrthods fi ir Disposal o f f l e d Water from the Continuous ?"7 Prproc~ss, Kadford Army Ammunition Plant, Kadford, Va., f'ebruary 1975.

Springer Verlag, Berlin 1928.

der Organischen Chrwzie, 4th ed . , Vol. 10/1, 'l'hieme Verlag, Stuttgart 1971, p. 859-860.

(12 ) E. E. Gilbert, Int. ./. SuVuV Cbcm., Part A, 2 ( 2 ) , 147 (1972) .

( 1 0 ) Beilsteins Handhuch der Organischen Chemie, 4th ed., Vol. XI,

(1 1) W. Seidenfaden and D. Pawellek, in: Houbcn-Weyl, Methoden


(13) S. Young, Recovery of Nitrobody f r o m Sulfite Liquors, Glasgow University Report No. 182, October 16, 1942.

(14) B. Batik, Cbim. e t Ind. (Paris). 29, 960 (1933). (15) A. Brown and H. F. Fisher,J. Amer. Chem. Soc. 98 ( l8) , 5682

(1976). We thank Mr. V. I. Siele for calling this reaction to our attention.

(16) L. C. Kurz and C. Frieden, ibid., 97, 679 (1975). (17) W. Zerweck, M. Schuberr, and R. Fleischhauer, German Patent

(18) 0. L. Brady and J. H. Bowman,J. Chem. Soc. 119, 894 (1921). (19) K. L. Hardie and K. H. 'l'homson, ibid., p. 2513 (1957). (20) M. Pezold, R. S. Schreiber, and R. L. Shriner, J . Amer. Chem.

(21) V. L. Sbarskii, G. M. Shutov, V. F. Zhilin, R. G. Chirkova, and

(22) P. E. Fanta, Chem. Rev. 64, 613 (1964). (23) M. Muraour, A r m y Ordnance 5, 507 (1925). (24) 'I. Urbanski, Chemistry and 7echnology of Explosiwes, Vol. 1,

PS 905,014 (1949); Chem. Abstr. 50, 12111 (1956).

Soc. 56, 696 (1934).

E. Yu. Orlova, Zh. Org. Khim. 7 (2) , 310 (1971).

Pergamon Press, New York 1967, p. 389.

(25) Beilsteins Handbuch der Orgdnischen Chemie, 4th ed., Vol. XII,

(26) Ibid., Vol. XV. . (27) 0. L. Brady and W. Gibson,J. Chem. Soc. 119, 98 (1921). (28) E. L. Brown and N. Campbell, ibid., p. 1699 (1937). (29) M. Busch and F. Gebelein, J . Prakt. Chem. (21, 1 1 5 , 107 (1927). (30) D. H. Rosenblatt and W. H. Dennis, Jr., Studies on the Reac-

tions of Nucleopbiles with T N T Isomers, Edgewood Arsenal 'Technical Report 4698, March 1973.

34, 175 (1918).

Springer Verlag, Berlin 1928.

(31) H. Ryan and W. M. O'Riordan, Proc. R. Irish. Akad., Sect. B,

(32) W. Qvist and M. Moilanen, Acta Acad. Abo. 14, No. 3, 6 (1943).

Acknowledgement. We are indebted to Mr. M. Warman for NMR spectra.

(Received September 14, 1977)

Documents

Recovery of Organic Values from TNT Purification Waste Water